The delivery of water in controlled minute amounts to internal combustion engines to retard and control combustion and improve engine operation is an old expedient disclosed in numerous prior patents. Such devices have met with varying degrees of acceptance and success. They vary widely in complexity and manufacturing costs and, in general, are either too simple to operate efficiently and effectively or too costly to be practical.
With the above in view, it is the object of this invention to provide a water delivery or injection system for engines which is uncomplicated and of relatively low manufacturing cost and which has the ability to operate effectively on demand under varying conditions of engine operation.
The heart of the invention resides in the provision of a three-way spool valve which is activated by engine manifold pressure and responds directly to the degree of such pressure through a suitable booster device to deliver exactly the proper amount of water to the air/fuel induction passage of the engine to satisfy engine demand at any given instant. The valve spool is spring-biased to a water bypass position, such as low idle, where little or no water is delivered through the valve to the engine. When the engine is shut off, no water can be delivered through the valve.
The valve is direct and positive in its control of water delivered to the engine and the water passages in the valve cooperating with the valve spool are dynamically sealed effectively from adjacent air actuation chambers of the valve. The valve is versatile in that it may be used to regulate the admission of water to a wide variety of engines for the purposes stated in the prior art.
Other features and advantages of the invention will become apparent during the course of the following description.